Prevalence of mast cell activation disorders and hereditary alpha tryptasemia among patients with postural orthostatic tachycardia syndrome and Ehlers-Danlos syndrome: A systematic review

Postural orthostatic tachycardia syndrome (POTS) and Ehlers-Danlos syndrome (EDS) are often reported to occur concurrently with mast cell activation disorders (MCADs) and hereditary alpha tryptasemia (HAT). However, it remains unclear whether evidence supporting this relationship exists. To determine the prevalence of MCADs and HAT in patients diagnosed with having EDS and or POTS. We conducted a systematic search of MEDLINE (OVID), EMBASE (OVID), Scopus, and Web of Science with the assistance of an experienced medical librarian. We focused on patients with any MCAD or HAT in conjunction with a diagnosis of POTS and/or EDS. A total of 200 records were screened, 107 were excluded based on the title or abstract, 92 full texts were reviewed, and 1 record was not retrieved. No studies were identified that met our primary criterion of including patients diagnosed with any MCAD or HAT alongside POTS and/or EDS based on our prespecified diagnostic criteria. Our review did not find evidence to confirm a relationship between MCADs, HAT, POTS, and EDS. However, it must be mentioned that 1 study revealed an association between mast cell activation syndrome, POTS, and EDS and came close to meeting the full diagnostic criteria for mast cell activation syndrome, unlike other studies. This indicates that further research using strict and validated diagnostic criteria is needed to clarify whether a true association between conditions exists.